Which of one provides hardness to cell wall ?

Options

A. Chloroplast
B. `S_(1)` layer of secondary wall
C. Tertiary wall
D. Primary wall

Answer

To answer the question "Which one provides hardness to the cell wall?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Components of Cell Walls**:
- Cell walls are primarily made up of cellulose, hemicellulose, and lignin. Each component plays a different role in the structure and function of the cell wall.

2. **Identify the Role of Lignin**:
- Lignin is a complex organic polymer that provides rigidity and hardness to the cell wall. It is especially important in the secondary cell wall.

3. **Differentiate Between Cell Wall Layers**:
- The cell wall consists of different layers: primary wall, secondary wall, and sometimes a tertiary wall. The secondary wall is where lignin is predominantly found.

4. **Evaluate the Options**:
- The options provided are chloroplast, S1 layer of secondary wall, tertiary wall, and primary wall.
- Among these, the S1 layer of the secondary wall is known to contain lignin, which contributes to the hardness of the cell wall.

5. **Select the Correct Answer**:
- Based on the information about lignin and its association with the secondary wall, the correct answer is the **S1 layer of the secondary wall**.

### Final Answer:
The S1 layer of the secondary wall provides hardness to the cell wall.

---